Homocysteine concentrations in adults with trisomy 21: effect of B vitamins and genetic polymorphisms12

• Published in: The American journal of clinical nutrition Vol. 80; no. 6; pp. 1551 - 1557
• Main Authors: Fillon-Emery, Nathalie, Chango, Abalo, Mircher, Clotilde, Barbé, Françoise, Bléhaut, Henri, Herbeth, Bernard, Rosenblatt, David S, Réthoré, Marie-Odile, Lambert, Daniel, Nicolas, Jean Pierre
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.12.2004
• Subjects: CBS; Down syndrome; folate; homocysteine; MTHFR; MTR; MTRR; polymorphism; RFC; trisomy 21; vitamin B-12; vitamin B-6; homocysteine; folate; vitamin B-6; MTRR; vitamin B-12; CBS; trisomy 21; MTHFR; polymorphism; MTR; Down syndrome; RFC
• ISSN: 0002-9165
• DOI: 10.1093/ajcn/80.6.1551

The effects of supplementation with B vitamins and of common polymorphisms in genes involved in homocysteine metabolism on plasma total homocysteine (tHcy) concentrations in trisomy 21 are unknown. We aimed to determine the effects of orally administered folic acid and of folic acid combined with vitamin B-12, vitamin B-6, or both on tHcy in adults with trisomy 21. The study was also intended to analyze the possible influence of gene polymorphisms. One hundred sixty adults with trisomy 21 and 160 healthy, unrelated subjects aged 26 ± 4 y were included. Plasma tHcy, red blood cell folate, serum folate, and vitamin B-12 were measured. Genotyping for the common methylenetetrahydrofolate reductase (MTHFR) 677C→T, MTHFR 1298A→C, cystathionine β-synthase 844Ins68, methionine synthase 2756A→C, methionine synthase reductase 66A→G, and reduced folate carrier 80G→A polymorphisms was carried out. The mean tHcy concentration (9.8 ± 0.7 μmol/L) of cases who did not use vitamins was not significantly different from that of controls (9.4 ± 0.3 μmol/L). Plasma tHcy concentrations (7.6 ± 0.3 mmol/L) in cases who used folic acid were significantly lower than in cases who did not. Folic acid combined with vitamin B-12 did not significantly change tHcy concentrations compared with those in cases who used only folic acid. Folic acid combined with vitamins B-6 and B-12 significantly lowered tHcy (6.5 ± 0.5 μmol/L). The difference in tHcy according to MTHFR genotype was not significant. However, tHcy concentrations were slightly higher in TT homozygotes among the controls but not among the cases. This study provides information on the relation between several polymorphisms in genes involved in homocysteine and folate metabolism in adults with trisomy 21.